<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>

</body>
<script>
  // 1. ==
  console.log(18 == 18);// => true
  console.log(18 == '18');// => true
  console.log(18 != 18);// => false
  console.log(18 != '18'); // => false

  // 2. ===
  console.log(18 === 18);// => true
  console.log(18 === '18');// => false


</script>
</html>